Relevant bibliographies by topics / Catalyc performance

Academic literature on the topic 'Catalyc performance'

Author: Grafiati
Published: 7 July 2024
Last updated: 7 July 2024

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  1. Journal articles
  2. Dissertations / Theses
  3. Books
  4. Book chapters
  5. Conference papers
  6. Reports

Journal articles on the topic "Catalyc performance":

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You, Dokyoung S., Karon F. Cook, Benjamin W. Domingue, Maisa S. Ziadni, Jennifer M. Hah, Beth D. Darnall, and Sean C. Mackey. "Customizing CAT Administration of the PROMIS Misuse of Prescription Pain Medication Item Bank for Patients with Chronic Pain." Pain Medicine 22, no. 7 (May 4, 2021): 1669–75. http://dx.doi.org/10.1093/pm/pnab159.

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Abstract Objective The 22-item PROMIS®-Rx Pain Medication Misuse item bank (Bank-22) imposes a high response burden. This study aimed to characterize the performance of the Bank-22 in a computer adaptive testing (CAT) setting based on varied stopping rules. Methods The 22 items were administered to 288 patients. We performed a CAT simulation using default stopping rules (CATPROMIS). In 5 other simulations, a “best health” response rule was added to decrease response burden. This rule stopped CAT administration when a participant selected “never” to a specified number of initial Bank-22 items (2–6 in this study, designated CATAlt2-Alt6). The Bank-22 and 7-item short form (SF-7) scores were compared to scores based on CATPROMIS, and the 5 CAT variations. Results Bank-22 scores correlated highly with the SF-7 and CATPROMIS, Alt5, Alt6 scores (r=0.87–0.95) and moderately with CATAlt2- Alt4 scores (r=0.63–0.74). In all CAT conditions, the greatest differences with Bank-22 scores were at the lower end of misuse T-scores. The smallest differences with Bank-22 and CATPROMIS scores were observed with CATAlt5 and CATAlt6. Compared to the SF-7, CATAlt5 and CATAlt6 reduced overall response burden by about 42%. Finally, the correlations between PROMIS-Rx Misuse and Anxiety T-scores remained relatively unchanged across the conditions (r=0.31–0.43, Ps < .001). Conclusions Applying a stopping rule based on number of initial “best health” responses reduced response burden for respondents with lower levels of misuse. The tradeoff was less measurement precision for those individuals, which could be an acceptable tradeoff when the chief concern is in discriminating higher levels of misuse.
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Aziz, Isalmi, Yessinta Kurnianti, Nanda Saridewi, Lisa Adhani, and Wahyu Permata. "Utilization of Coconut Shell as Cr2O3 Catalyst Support for Catalytic Cracking of Jatropha Oil into Biofuel." Jurnal Kimia Sains dan Aplikasi 23, no. 2 (February 17, 2020): 39–45. http://dx.doi.org/10.14710/jksa.23.2.39-45.

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Coconut shell waste is a waste that has a high carbon content. Carbon in coconut shell waste can be converted into activated carbon having a large surface area. This potential property is suitable to apply the coconut shell as catalyst support. To increase the catalytic activity, metal oxides such as Cr2O3 are impregnated. The purpose of this study is to synthesize Cr2O3/carbon catalyst and test its catalytic activity on catalytic cracking of Jatropha oil. The first stage was the synthesis of activated carbon and the determination of its proximate and ultimate. The second step was impregnation to produce Cr2O3/carbon catalyst. Furthermore, X-Ray Diffraction to determine crystallinity, Surface Area Analyzer to identify its surface area and Fourier Transform Infrared to analyze functional groups. Then the catalytic activity was tested on the catalytic cracking of Jatropha oil. In addition, the chemical compound composition and biofuel selectivity of the catalytic cracking product was determined using Gas Chromatography-Mass Spectrometer. Proximate analysis results showed that activated carbon contains 9%, 1%, 23%, and 67% of water, ash, evaporated substances, and bound carbon, respectively. The results of the ultimate analysis resulted in carbon (C), hydrogen (H), and nitrogen (N) contents of 65.422%, 3.384%, and 0.465%, correspondingly. The catalyst crystallinity test showed the presence of Cr2O3 peaks at 2θ: 24.43°; 33.47° and 36.25° according to JCPDS No. 84-1616. In the absorption area of 400-1000 cm-1 and the range of 2000 cm-1 showed the presence of Cr-O stretching due to Cr2O3 adsorbed into the activated carbon structure. The surface area of activated carbon and Cr2O3/carbon catalysts with a concentration of 1.3, and 5% was 8.930 m2/g; 47.205 m2/g; 50.562 m2/g; and 38.931 m2/g, respectively. The catalytic activity test presented that the best performance was showed by Cr2O3/carbon catalyst with a concentration of 5% indicated by conversion of Jatropha oil into biofuel of 67.777% with gasoline selectivity, kerosene, and diesel of 36.97%, 14.87%, and 15.94%, correspondingly.
3

Scheiner, Justin J., Andrew Labay, and Jim Kamas. "Rootstocks Improve Blanc Du Bois Vine Performance and Fruit Quality on Alkaline Soil." Catalyst: Discovery into Practice 4, no. 2 (May 4, 2020): 63–73. http://dx.doi.org/10.5344/catalyst.2020.19007.

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Akanbi, Felicia Kehinde, and Adeniyi Temitope Adetunji. "Information Management: A Catalyst to Organizational Performance among University Employees." International Journal of Psychosocial Rehabilitation 24, no. 02 (February 12, 2020): 2649–58. http://dx.doi.org/10.37200/ijpr/v24i2/pr200560.

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Li Hao, 李浩, 周庆欣 Zhou Qingxin, 马生华 Ma Shenghua, and 王刚 Wang Gang. "光热膜的制备以及光芬顿催化性能的研究." Laser & Optoelectronics Progress 58, no. 19 (2021): 1916001. http://dx.doi.org/10.3788/lop202158.1916001.

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Fahmi, Fahmi, Widiyastuti Widiyastuti, and Heru Setyawan. "Graphitization of Coconut Shell Charcoal for Sulfonated Mesoporous Carbon Catalyst Preparation and Its Catalytic Behavior in Esterification Reaction." Bulletin of Chemical Reaction Engineering & Catalysis 15, no. 2 (June 26, 2020): 538–44. http://dx.doi.org/10.9767/bcrec.15.2.7745.538-544.

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Here, we reported the utilization of coconut shell charcoal used for solid acid catalysts and its performance in the esterification reaction of acetic acid and methanol. The graphitization of coconut shell charcoal was carried out by the calcination and KOH activation at the temperature of 400 °C for an hour and continued at the temperature of 800 °C for an hour under nitrogen flow resulted in graphitic carbon. The effect of the addition of KOH activation was observed by varied the weight ratio of coconut shell charcoal as raw material (RM) and KOH. The selected weight ratio of RM:KOH was 1:1, 1:2, and 1:4. The resulted graphitic carbon was sulfonated by heating with the sulfuric acid to obtain a solid acid catalyst. The sulfonic time was evaluated for 5 and 10 hours. The generated particles were characterized to examine the morphology, the crystallinity, the specific surface area, the chemical bonding, and the ionic capacity using Scanning Electron Microscopy (SEM), X-Ray diffraction (XRD), nitrogen gas absorption-desorption, Fourier Transform Infrared Spectroscopy (FTIR), and titration method, respectively. The best condition for graphitization of raw material is the use of RM:KOH = 1:4, resulting in the highest surface area reaching 1259.67 m2/g and the most dominant of the sulfonic group of −SO3 bond. Furthermore, increasing the sulfonating time from 5 to 10 hours led to the increase of the yield of esterification reaction from 85% to 96.57% for graphite synthesized using RM:KOH = 1:4. Copyright © 2020 BCREC Group. All rights reserved
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Moyer, Michelle M., Jensena M. Newhouse, and Maria S. Mireles. "Performance of Early Fruit-Zone Leaf Removal in Cabernet Sauvignon and Merlot in an Arid Climate." Catalyst: Discovery into Practice 6, no. 1 (November 18, 2021): 20–29. http://dx.doi.org/10.5344/catalyst.2021.21007.

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London, John. "Catalan Theater Without Catalan? Plays and Performances: 1939-1945." Catalan Review 23 (January 2009): 191–209. http://dx.doi.org/10.3828/catr.23.1.191.

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Shukla, Vinayak, and Prof Yogesh Tembhurne. "A Review on Performance Enhancement of Catalytic Conveter by Making Geometrical Changes." International Journal of Trend in Scientific Research and Development Volume-2, Issue-4 (June 30, 2018): 629–34. http://dx.doi.org/10.31142/ijtsrd13058.

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Kearns, William K., Richard Koshgarian, and Jeffrey H. Renshaw. "American Orchestral Music: A Performance Catalog." Notes 50, no. 4 (June 1994): 1451. http://dx.doi.org/10.2307/898347.

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You might also be interested in the extended bibliographies on the topic 'Catalyc performance' for particular source types:
Journal articles Dissertations / Theses Books

Dissertations / Theses on the topic "Catalyc performance":

1

Rua, Gonzalez Diego. "Synthèse de matériaux catalytiques de type oxydes mixtes pour la production de méthanol par la précipitation en flux continu en système microfluidique." Electronic Thesis or Diss., Strasbourg, 2024. http://www.theses.fr/2024STRAF001.

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Le réchauffement climatique est une préoccupation pour les générations actuelles et futures en raison de l'augmentation des émissions de gaz à effet de serre (GES) dans l'atmosphère, principalement dues à la dépendance aux combustibles fossiles. L'utilisation de carburants alternatifs tels que le méthanol durable produit à partir de H2 renouvelable et de CO2 contribuerait à réduire les émissions de GES et les effets du changement climatique. La synthèse du méthanol à partir de matières premières riches en CO2 se fait préférentiellement en utilisant un catalyseur solide composé de CuO, ZnO et ZrO2. Ce type de catalyseur peut être produit par coprécipitation des espèces métalliques à l'aide d'un dispositif microfluidique, avec des avantages qui ont été démontrés par rapport aux catalyseurs synthétisés par coprécipitation discontinue. Dans ce travail, différents catalyseurs pour l'hydrogénation du CO2 en méthanol ont été synthétisés en utilisant la technique microfluidique dans différentes conditions, afin d'explorer différents paramètres de synthèse pouvant conduire au développement de catalyseurs plus actifs. Les différences de propriétés et d'activité entre un catalyseur synthétisé par la méthode microfluidique et un autre synthétisé par la méthode batch ont été étudiées, suivies d'une exploration des effets du temps de vieillissement et de la température de coprécipitation sur les catalyseurs. Enfin, l'effet de différentes compositions de catalyseurs sur les propriétés et l'activité a été déterminé, en étudiant différentes teneurs en CuO, l'utilisation de CeO2 comme promoteur et l'utilisation de In2O3 comme promoteur et comme métal actif
Global warming is a concern for the current and future generations due to the increasing greenhouse gases (GHG) emissions to the atmosphere, mainly due to the dependence on fossil fuels. The use of alternative fuels such as sustainable methanol produced from renewable H2 and from CO2 would contribute to reduce the GHG emissions and the effects of climate change. The synthesis of methanol using CO2 rich feedstock is preferentially done by using a solid catalyst composed of CuO, ZnO and ZrO2. This type of catalyst can be produced by coprecipitation of the metal species using a microfluidic device, with advantages that have been demonstrated over catalysts synthesized by batch coprecipitation. In this work, different catalysts for the hydrogenation of CO2 to methanol were synthesized using the microfluidic technique under different conditions, in order to explore different synthesis parameters that could lead to the development of more active catalysts. The differences in the properties and activity between a catalyst synthesized by the microfluidic method and another synthesized by the batch method were investigated, followed by an exploration of the effects of the aging time and the coprecipitation temperature on the catalysts. Lastly, the effect of different compositions of catalysts on the properties and activity were determined, by investigating different CuO contents, the use of CeO2 as a catalyst promoter, and the use of In2O3 as a catalyst promoter and as active metal
2

Deshpande, Nitish. "Catalytic Material Design: Design Factors Affecting Catalyst Performance for Biomass and FineChemical Applications." The Ohio State University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=osu154273906480973.

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Tangale, N. P. "Zeolite based micro-mesoporous composites: synthesis, characterization and catalytic performance as heterogeneous catalyst for valorization of sugar." Thesis(Ph.D.), CSIR- National Chemical Laboratory, Pune, 2018. http://dspace.ncl.res.in:8080/xmlui/handle/20.500.12252/4576.

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Haimad, N. "A theoretical and experimental investigation of the flow performance of automotive catalytic converters." Thesis, Coventry University, 1997. http://curve.coventry.ac.uk/open/items/3f51aa95-571c-73d5-bee3-4b523cab0a1c/1.

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Considerable research is being carried out into the parameters that affect catalyst performance in order to meet the latest emission regulations. The conversion efficiency and the durability of automotive catalytic converters are significantly dependent on catalyst flow performance. Related investigations are commonly conducted using CFD techniques which represent an inexpensive and fast alternative to experimental methods. This thesis focuses on the flow performance of automotive catalytic converters using both experimental and computational techniques. The work describes the effects of inlet flow conditions on catalyst performance, the application of radial vanes to catalyst systems and the refinement of the CFD flow model which increases the accuracy of the predicted catalyst flow performance. the effects of inlet flow conditions on the flow maldistribution across the catalyst face and the total pressure loss through the system were assessed using a steady air flow rig. Tests were conducted over a range of Reynolds numbers typically encountered in automotive catalytic converters using a uniform and a fully-developed inlet flow condition. The results showed that the flow maldistribution significantly increases with Reynolds number notably in wide-angled diffusers. The catalyst flow performance is considerably improved when the inlet flow is uniform rather than fully-developed, the non-dimensional total pressure loss is reduced by 8% at Re=60000 and the flow maldistribution across the catalyst face is decreased by 12.5% and 15% respective Reynolds numbers of 30000 and 60000 when using a 60 degree diffuser. The total pressure loss through the system was found to be mostly associated with the monolith brick resistance. When the flow maldistribution is approximately 2, the pressure loss across the monolith brick represents 80% of the system pressure loss. The flow maldistribution across the catalyst face was improved by locating a system of radial splitters in the diffuser. The optimum flow performance was found to be a complex function of the vane design. A maximum improvement in the flow maldistrution indices M and Mi of 25% and 50% respectively was achieved at the expense of an increase in total pressure loss of 13.5% at Re = 60000. Both CFD and flow visualisation techniques were used as an aid to interpreting the flow field in the diffuser. Although a qualitative agreement was obtained using CFD, the flow maldistribution across the catalyst face was underpredected by up to 20%. The accuracy of the flow predictions was significantly improved by investigating the flow field in the monolith channels. Flow recirculation occurs in the channel entry length when the flow approaches the monolith channels at an angle which induces an additional implemented into four models of the flow through axisymmetric catalyst assemblies using various diffuser geometries and inlet flow conditions. By including the flow entrance effects in the porous media approach, the flow maldistribution was predicted within 8% instead of 15% when these effects are neglected. Further investigation of the flow in the monolith channels will be required to accurately model three-dimentional flows (racetrack catalysts) and to include various channel geometries and system flow rates.
5

Inayat, Amer [Verfasser], and Wilhelm [Akademischer Betreuer] Schwieger. "Open-cell Foams as Catalyst Support: A Description of Morphology, Fluid Dynamics and Catalytic Performance / Amer Inayat. Gutachter: Wilhelm Schwieger." Erlangen : Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 2014. http://d-nb.info/1054342253/34.

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Lin, ChienShung. "Effect of wall thermal conductivity on the performance of Swiss roll combustors using ammonia pretreated Pt catalyst for catalytic reaction." Pullman, Wash. : Washington State University, 2009. http://www.dissertations.wsu.edu/Thesis/Spring2009/C_Lin_040609.pdf.

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Thesis (M.S. in mechanical engineering)--Washington State University, May 2009.
Title from PDF title page (viewed on May 27, 2009). "School of Mechanical and Material Engineering." Includes bibliographical references (p. 45-47).
7

Lakshmanan, Alagendran. "RFID : a catalyst for supply chain performance." Thesis, Jönköping University, JIBS, Centre of Logistics and Supply Chain Management, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-8068.

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THE ADVANTAGE OF RFID TECHNOLOGY IMPLEMENTATION IN A MANUFACTURING FIRM. THE TECHNOLOGY IMPLEMENTATION STREAM LINES THE LOSS OF INFORMATION FLOW WHEN THE PRODUCT MOVES ALONG THE DIFFERENT CHAIN MEMBERS. THE COMMON SHARING OF THE ASSOCIATED BENEFIT BRINGS HIGHER PROCESS EFFICEINCY , WHEN THE PRODUCT MOVES ALONG THE UPSTREAM AND DOWNSTREAM SUPPLY CHAIN FOR THE SELECTED PRODUCT. THE IMPLEMENTATION IS A CUSTOMISED SOLUTION FOR THE MANUFACTURING UNIT FOR ITS PRODUCT, THIS THESIS WILL ENABLE THE IMPLEMENTATORS THE VALUABLE IMPLEMENTATION PROCEDURES THAT ONE HAS TO FOLLOW TO TAKE RIGHT BENEFIT FROM THIS TECHNOLOGY.

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Todd, Heather Elizabeth. "Investigating catalyst performance in batch reactive distillation." Thesis, University of Newcastle Upon Tyne, 2011. http://hdl.handle.net/10443/1244.

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Reactive distillation (RD) combines chemical synthesis with separation by distillation, but this leads to a non-trivial system: the hardware selection, the system components, the mode of operation and the operating conditions all affect the performance of the RD process. A key process development issue is the identification of suitable catalysts that perform well under reactive distillation conditions, as catalysts are crucial for increasing reaction rate when operating temperature range is limited by evaporation. The main goal of this research is to develop a method, utilizing high throughput technology, which can be used to assess many candidate catalysts for batch RD systems. The identification of potentially suitable catalysts should be made as early as possible, but before experimental work begins the only information available is the catalyst composition and structure. The approach taken in this research is to correlate catalyst properties to the performance in RD tests and the outputs from the dynamic simulations. The case study used is a batch reactive distillation for the esterification of a long-chain fatty acid. Potential catalysts are studied at small scale in a high throughput platform, and further investigation if performaed in an experimental batch RD unit. The most active of the screened catalysts, sulfuric acid and MSA also have the highest initial activity under RD. Heteropoly acids appear to have a good activity level, while ferric sulfate gives intermediate but apparently increasing activity. Some outcomes of the RD experiments were unexpected: the strong homogeneous acid catalysts entail low distillate water yield, and some metal acetates had higher activity than anticipated in the RD tests. This demonstrates that pilot scale experiments currently remain necessary for the evaluation of catalyst performance for RD processes. The insights gained from this study lead to key recommendations for future studies: an increased scope of study with a larger number of candidates which preferable have similar structure; evaluation of additional catalyst performance indicators, performed over the full operating temperature range; use of the smallest suitable experimental column; and more focus on physical factors such as solubility. Use of a simulator with an established physical property calculation tool is essential for successful simulations of batch RD.
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Zhan, Xiaotong. "Heterogeneous catalysis in microreactors : study of the performance of various supports." Thesis, Ecole centrale de Marseille, 2018. http://www.theses.fr/2018ECDM0007/document.

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Cette étude présente la préparation et l’évaluation de l’activité d’un nouveau catalyseur monolithique en microréacteur. La réaction d’hydrogénation du p-nitrophénol par transfert d’hydrogène avec l’acide formique a été choisie comme réaction modèle pour comparer les performances du monolithe à celles d’un catalyseur commercial en lit fixe.Cette thèse comporte une partie expérimentale importante. D’un côté, un montage expérimental et des protocoles d’analyse en ligne ont été mis au point pour faire une étude quantitative précise de la réaction modèle. De l’autre côté, les conditions de préparation d’un monolithe de silice fonctionnalisée dans le tube-réacteur en acier chemisé de verre ont été optimisées. Il a été chargé en nanoparticules de Pd par une méthode en écoulement. Le monolithe comporte un réseau de macropores pour l’écoulement et une organisation hexagonale typique de mésopores et micropores, et cela presque sans retrait au séchage. L’activité des 2 types de catalyseurs dans la réaction modèle a été comparée par leur cinétique de réaction et leur comportement dynamique dans la phase de mise en régime du microréacteur. Une partie théorique présente la modélisation du microréacteur en régime stationnaire pour l’établissement des cinétiques et en régime transitoire pour rationaliser les observations expérimentales. Le monolithe Pd@silice et le catalyseur commercial Pd@alumine ont des comportements différents et obéissent à des lois cinétiques différentes. Un modèle réactionnel impliquant un changement de propriétés de la surface catalytique pourrait expliquer le profil de concentration inhabituel observé avec le catalyseur commercial. La comparaison démontre la supériorité du nouveau catalyseur monolithe, et lui ouvre de bonnes perspectives industrielles
This study presents the preparation and the evaluation of performance of a new monolithic catalyst in microreactor. The transfer hydrogenation of p-nitrophenol by formic acid is chosen as the model reaction for the comparison of the monolith with a traditional packed-bed microreactor containing commercial catalyst.This thesis includes an important experimental part. On the one hand, experimental set-up and protocols involving on-line analysis have been developed in order to study quantitatively the model reaction; On the other hand, the conditions of preparation of functionalized silica monolith in a stainless steel tube with the inner wall pre-coated by glass were optimized, and the palladium nanoparticles were immobilized by a continuous flow method. The monolith possesses the flow-through macropores, typical hexagonal organization of mesopores and micropores, and scarcely any shrinkage. The comparison of the two types of catalysts mainly focuses on the activity of catalysts in the model reaction, their kinetic model and their dynamic behavior in the start-up phase of the flow microreactor. In the theoretical part, the modelisation of reactor has been investigated both under stationary conditions for kinetics determination and under transient conditions for the rationalization of experimental observations. Pd@silica monolith and commercial Pd@alumina powder have different behavior and gives different kinetic laws. A reaction model with change in the catalytic surface properties could explain the unusual profile of concentrations observed with commercial catalyst. The superior performance of monolithic catalyst is demonstrated, which also exhibits particular industrial interests
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Afshar, Farniya Ali. "Development and performance analysis of autonomous catalytic micropumps." Doctoral thesis, Universitat Autònoma de Barcelona, 2014. http://hdl.handle.net/10803/284892.

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Uno de los principales retos de la ingeniería de nanomotores, además de las dificultades para fabricar objetos nanométricos complejos, es cómo proveerles de energía para que funcionen. La aplicación de campos externos es una forma común y fácil de impulsar motores relativamente grandes. Sin embargo, cuando el tamaño de los motores se hace más pequeño, la transferencia de energia desde la escala macroscópica a la nanoescala se vuelve más problemática. Por lo tanto, el desarrollo de sistemas a nivel de la nanoescala totalmente autónomos que puedan generar su propia energía para poder autopropulsarse es muy deseable. Los sistemas biológicos ofrecen numerosos ejemplos de micro/nano motores autónomos. El punto clave detrás de la eficiente maquinaria biológica es la conversión de energía química en movimiento direccional. Por lo tanto existe un alto interés en crear nuevos motores artificiales que puedan auto-impulsarse y realizar actividades autónomas de forma similar a la impresionante maquinaria molecular de los organismos vivos. Recientemente se ha comenzado una intensa actividad científica en el desarrollo de motores y sistemas de bombeo propulsados químicamente en base a la auto-generación local de gradientes. El presente trabajo de investigación trata sobre el concepto de microsistemas de bombeo catalítico que fue reportado por primera vez en 2005. Un microsistema de bombeo catalítico es un sistema activo que tiene la capacidad de inducir fenómenos electrohidrodinámicos a partir de una reacción (electro)química sobre una micro/nano estructura bimetálica. Aunque los dispositivos catalíticos han sido objeto de investigaciones anteriores en el que sus aplicaciones nanotecnológicas han comenzado a demostrarse, el mecanismo de actuación quimio-mecánica ha sido menos estudiado. Esto es en parte debido a la compleja interrelación que existe entre las reacciones catalíticas y los fenómenos electro-hidrodinámicos. Como consecuencia de ello todavía hay una serie de preguntas sin resolver que requieren mayor investigación para establecer el rol desempeñado por los diferentes procesos y lograr una mejor comprensión del mecanismo detrás de ellos. Por lo tanto, en esta tesis doctoral se ha realizado una caracterización exhaustiva de la actuación quimio-mecánica para entender los principales factores fisicoquímicos que regulan el mecanismo de funcionamiento de microbombas bimetálicas de Au- Pt en presencia de peróxido de hidrógeno como combustible. Las investigaciones han sido solventadas no sólo con resultados experimentales sino también con simulaciones numéricas. Estos estudios fundamentales son relevantes no sólo para estos sistemas de bombeos catalíticos, sino también para micro/nanomotores o nanorobots suspendidos en fluidos o coloides activos autopropulsados. Los estudios se han extendido también a otras estructuras bimetálicas ( Au- Ag , Au- Ru , Au -Rh , Cu - Ag , Cu - Ni, Ni- Ru y Ni- Ag) y a dispositivos semiconductores/metálicos ( Si dopado p / Pt , Si dopado n / Pt) con la idea de evaluar sus potencialidades como sistemas de bombeo catalítico en presencia del mismo combustible químico. En el caso de los sistemas metal/semiconductor su funcionamiento se basa en la fotoactivación de reacciones catalíticas, lo que proporciona un valor añadido a estas bombas y permite el desarrollo de nuevos interruptores foto-electrohidrodinámicos. Estos logros pueden abrir nuevas y prometedoras líneas de investigación en el campo de los actuadores y nanomotores catalíticos. El trabajo de tesis describe también una de las posibles aplicaciones de estos dispositivos activos que está relacionada con el transporte y depósito de materia en lugares específicos de un sustrato guiado por los fenómenos electrohidrodinámicos locales. Eso permite fabricar superficies nanoestructuradas de forma autónoma con un gran impacto nanotecnológico en una amplia gama de campos.
One of the main challenges in the engineering of nanomachines, besides the difficulties to fabricate complex nanometric objects, is how to power them. The application of external fields is a common and easy way to actuate relatively large machines. However, when the size of the machines becomes smaller, the transfer of power from the macroscopic scale to the nanoscale becomes problematic. Therefore, the development of fully autonomous nanoscale systems which can self-generate their required power is very desirable. Biological systems are the source of numerous examples of natural micro/nanoscale autonomous motors. The conversion of chemical energy into directional motion is the key point behind the high efficient nanofactory of biomolecular machines. Therefore there is a high interest to create novel artificial machines which can self-propel and perform autonomous activities in a similar way the impressive molecular machinery does in living organisms. Many research activities have recently focused on chemically powered motors and micropumps based on the local self-generation of gradients. The present research work deals with the catalytic micropump concept which was reported for the first time in 2005. A catalytic micropump is an active system which has the capability of triggering electrohydrodynamic phenomena due to an (electro)chemical reaction taken place on a micro/nano bimetallic structure. Although catalytic devices have been the subject of previous reports in which their nanotechnological applications have started to be demonstrated, the mechanism of the chemo-mechanical actuation has been less studied. That is in part due to the complex interrelation between the catalytic reactions and the electro-hydrodynamic phenomena. As a consequence there is still a number of intriguing questions that require further investigation for establishing the role played by the different processes and for achieving a better understanding of the mechanism behind them. Therefore, the research was focused on the full characterization of the chemomechanical actuation and the understanding of the main physicochemical factors governing the operating mechanism of Au-Pt bimetallic micropumps in presence of hydrogen peroxide fuel. The investigations were supported not only by experimental findings but also by numerical simulations. These fundamental studies are of high importance not only for catalytic micropumps but also for other autonomous micro/nano swimmers or active self-propelled colloids. The studies were also extended to other bimetallic structures (Au-Ag, Au-Ru, Au-Rh, Cu-Ag, Cu-Ni, Ni-Ru and Ni-Ag) and to semiconductor/metallic structures (p-doped Si/Pt, n-doped Si/Pt) to evaluate their potentialities as catalytic micropumps in presence of the same chemical fuel. In the last case photoactivation of the catalytic reactions can be accomplished which provides an added value to these pumps as novel photochemical-electrohydrodynamic switches. These achievements can open new and promising research activities in the field of catalytic actuators and nanomotors. The thesis work also describes one of the potential applications of these active devices which is related to the autonomous material guiding and self-assembly on particular locations of a sample. That allows fabricating nanostructured surfaces in an autonomous way with potential nanotechnological impact in a wide range of fields.
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Books on the topic "Catalyc performance":

1

Koshgarian, Richard. American orchestral music: A performance catalog. Metuchen, N.J: Scarecrow Press, 1992.

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Harrington, H. J. Organizational alignment handbook: A catalyst for performance acceleration. Boca Raton: CRC Press, Taylor & Francis Group, 2012.

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United States. Federal Highway Administration. Office of Highway Information Management., ed. Highway performance monitoring system catalog: New technology and techniques. [Washington, D.C.?]: Dept. of Transportation, Federal Highway Administration, Office of Highway Information Management, 1998.

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Peyrebrune, Henry L. Highway performance monitoring system catalog: New technology and techniques. [Washington, D.C.?]: Dept. of Transportation, Federal Highway Administration, Office of Highway Information Management, 1998.

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United States. Federal Highway Administration. Office of Highway Information Management., ed. Highway performance monitoring system catalog: New technology and techniques. [Washington, D.C.?]: Dept. of Transportation, Federal Highway Administration, Office of Highway Information Management, 1998.

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George, David J. Sergi Belbel and Catalan theatre: Text, performance and identity. Woodbridge, Suffolk [England]: Tamesis, 2010.

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John, Gillespie. Piano performance video recordings on VHS: A selected catalog. Lanham, Md: Scarecrow Press, 2003.

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Elliot, Paul. Mixing and crystallisation conditions in supported nickel catalyst preparation and their influence on catalyst performance. Birmingham: University of Birmingham, 1990.

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Community Training and Assistance Center. Catalyst for change: Pay for performance in Denver : final report. Boston, MA: Community Training and Assistance Center, 2004.

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Cavanaugh, Kraig E. Frustrated blonde: An exhibition of six southern California painters, John Breitweiser, J.L. Cooling, Amanda Farber, Dan Fuller, Carlo Marcucci, Greg Reser. San Diego, CA: Sushi Performance and Visual Art, 1993.

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Book chapters on the topic "Catalyc performance":

1

Deng, Jiayao, Xiao Hu, Gnauizhi Xu, Zhanfeng Deng, Lan Yang, Ding Chen, Ming Zhou, and Boyuan Tian. "The Preparation of Iridium-Based Catalyst with Different Melting Point-Metal Nitrate and Its OER Performance in Acid Media." In Proceedings of the 10th Hydrogen Technology Convention, Volume 1, 61–68. Singapore: Springer Nature Singapore, 2024. http://dx.doi.org/10.1007/978-981-99-8631-6_6.

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AbstractOxygen evolution reaction (OER) is the main factor limiting the large-scale development of proton-exchange membrane (PEM) hydrogen production. It is urgent to develop catalysts with excellent OER catalytic performance and stability. Herein, several Iridium-based catalysts were prepared by simple mixing and calcination, the OER properties of catalysts with different melting points of nitrates as calcinating additives were investigated. The RbNO3 treated catalyst displayed a low overpotential(η) of 297.6 mV versus RHE, which is lower than the catalyst calcinated without nitrate (323.8 mV vs. RHE). Moreover, the RbNO3 treated catalyst displayed good acid stability over 20 h Chronopotentiometric test. The high OER catalytic activity and stability of RbNO3 treated catalyst may be attribute to the smaller nanoparticle morphology, pure IrO2 structure and high electrochemical surface area (ECSA), which increase the number of active sites and the intrinsic catalytic activity. This work indicated that the catalyst with excellent OER performance can be obtained by selecting nitrate with moderate melting point as the calcinating additive. Nitrates (like RbNO3) treated catalyst with excellent catalytic activity and stability has good application prospect in hydrogen production of PEM water splitting.
2

Mirzaee, Mahdi, Mahmood Norouzi, Adonis Amoli, and Azam Ashrafian. "Catalytic Performance of Metal Alkoxides." In Advanced Catalytic Materials, 225–70. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2015. http://dx.doi.org/10.1002/9781118998939.ch7.

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Gao, Yuanfeng, Hong Lv, Yongwen Sun, Han Yao, Ding Hu, and Cunman Zhang. "Enhancement of Acidic HER by Fe Doped CoP with Bimetallic Synergy." In Proceedings of the 10th Hydrogen Technology Convention, Volume 1, 465–74. Singapore: Springer Nature Singapore, 2024. http://dx.doi.org/10.1007/978-981-99-8631-6_45.

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AbstractCompared to single metal site catalysis, the bimetallic synergistic strategy can exploit the complementary ability of different active sites for active species uptake and desorption to develop excellent catalysts. Pure phase metal phosphides are a disadvantage as a promising electrocatalyst for platinum-free hydrogen precipitation with either too strong or too weak adsorption of hydrogen. Here, synthetic Fe-doped CoP particles anchored with MWCNTs, which exhibited excellent catalytic performance for HER, required an overpotential of 123 mV to reach 10 mA cm−2, with a Tafel slope of 58.8 mV dec−1. It was found experimentally that Fe doping improved the conductivity of the catalyst regulated the electronic structure of CoP, and optimized the overall hydrogen adsorption energy of the catalyst. The difference in hydrogen adsorption strength of Fe, Co is used to break the symmetry constraint of single active center and improve the intrinsic activity of the catalyst, a strategy that can be used to guide the preparation of inexpensive and high performance catalysts.
4

Friedman, Avner. "Modeling catalytic converter performance." In Mathematics in Industrial Problems, 70–77. New York, NY: Springer New York, 1991. http://dx.doi.org/10.1007/978-1-4613-9177-7_7.

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Barr, Adrian, and Diana Blom. "Curriculum as catalyst." In Teaching and Evaluating Music Performance at University, 227–36. [1.] | New York : Routledge, 2020. | Series: ISME global perspectives: Routledge, 2020. http://dx.doi.org/10.4324/9780429328077-16.

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Zhao, Fu Jun, Lin Hai Han, and Long Liang. "Catalyst-Free Synthesis of Mullite Nanosticks." In High-Performance Ceramics V, 812–14. Stafa: Trans Tech Publications Ltd., 2008. http://dx.doi.org/10.4028/0-87849-473-1.812.

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Liu, Jing, and Tong Zhang. "Design of Membrane Electrode Assembly with Non-precious Metal Catalyst for Self-humidifying Proton Exchange Membrane Fuel Cell." In Proceedings of the 10th Hydrogen Technology Convention, Volume 1, 401–11. Singapore: Springer Nature Singapore, 2024. http://dx.doi.org/10.1007/978-981-99-8631-6_39.

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AbstractHigh cost is one of the key factors restricting the industrialization and commercialization of proton exchange membrane fuel cells (PEMFCs). In this paper, a low-cost membrane electrode assembly (MEA) is prepared by using a self-made non-precious metal catalyst. Through the polarization curve test of fuel cell, the optimal loading of Fe-N-S-C catalyst and the optimal ratio with Nafion ionomer are studied. When the loading of Fe-N-S-C catalyst is 2.0 mg cm−2 and the ratio of Nafion ionomer to Fe-N-S-C catalyst is 3:7, the performance of the PEMFC is the best. The performance of MEA under different relative humidity (RH) and inlet pressure is also explored. The experimental results show that the MEA can still maintain good performance under the condition of 40% RH, which shows that this MEA has a certain self-humidifying ability. Because the non-precious metal catalyst layer is too thick, the performance of PEMFC can be improved by increasing the inlet pressure appropriately. The durability of MEA with non-precious metal catalyst is poor, and there is still a lot of work to be done to improve the stability and durability.
8

Thomas, J. M. "Structure and Catalytic Performance of Zeolites." In Chemistry and Physics of Solid Surfaces VI, 107–32. Berlin, Heidelberg: Springer Berlin Heidelberg, 1986. http://dx.doi.org/10.1007/978-3-642-82727-3_6.

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Magee, John S., and Warren S. Letzsch. "Fluid Cracking Catalyst Performance and Development." In ACS Symposium Series, 349–71. Washington, DC: American Chemical Society, 1994. http://dx.doi.org/10.1021/bk-1994-0571.ch025.

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Mills, G. A. "Relationships Between Catalyst Production and Performance." In Inorganic Reactions and Methods, 60–64. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2007. http://dx.doi.org/10.1002/9780470145319.ch27.

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Conference papers on the topic "Catalyc performance":

1

Du, Yongbo, Chang’an Wang, Xiaoyang Wei, Qiang Lv, Yonggang Zhao, Peiqing Cao, Lei Deng, and Defu Che. "The Regeneration Effect of H2SO4 on V-W-TiO2 SCR Catalyst Deactivated by Alkali Metal." In ASME 2017 Power Conference Joint With ICOPE-17 collocated with the ASME 2017 11th International Conference on Energy Sustainability, the ASME 2017 15th International Conference on Fuel Cell Science, Engineering and Technology, and the ASME 2017 Nuclear Forum. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/power-icope2017-3144.

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The sodium content in Zhundong coal is extremely high, which can accelerate the deactivation of the V-W-TiO2 selective catalytic reduction (SCR) catalysts. Sulfuric acid solution (H2SO4) washing has been verified as a famous method to regenerate the de-NOx performance for catalyst which has been poisoned by alkali metals. However, the performance of the regenerated catalyst in practice still needs to be investigated. In the present study, the resistance to sulfur dioxide (SO2) and the mechanical strength of the regenerated catalyst were experimentally studied as well as the continuous operation performances under several conditions. The results indicate that the de-NOx activity of H2SO4 regenerated catalyst is chemically stable below 300 °C and thermally stable below 450 °C. However, the catalytic activity of the regenerated catalyst could suffer a decline during operating under the SCR atmosphere at 450 °C, which is different from the fresh catalyst. Besides, the regenerated catalyst shows good SO2 resistance, whereas the mechanical strength is likely to be affected by the H2SO4 washing treatment.
2

Hui, K. S., Christopher Y. H. Chao, C. W. Kwong, and M. P. Wan. "Performance of Transition Metal Ions Exchanged Zeolite 13X in Greenhouse Gas Reduction." In ASME 2007 International Mechanical Engineering Congress and Exposition. ASMEDC, 2007. http://dx.doi.org/10.1115/imece2007-41360.

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This study investigated the performance of multi-transition metal (Cu, Cr, Ni and Co) ions exchanged zeolite 13X catalysts on methane emission abatement, especially at methane level of the exhaust from natural gas fueled vehicles. Catalytic activity of methane combustion using multi-ions exchanged catalyst was studied under different parameters: mole % of metal loading, inlet velocity and inlet methane concentration at atmospheric pressure and 500 °C. Performance of the catalysts was investigated and explained in terms of the apparent activation energy, number of active sites and BET surface area of the catalyst. This study showed that the multi-ions exchanged catalyst outperformed the single-ions exchanged and the acidified 13X catalysts. Lengthening the residence time could also lead to higher methane conversion %. Catalytic activity of the catalysts was influenced by the mole % of metal loading which played important roles in affecting the apparent activation energy of methane combustion, active sites and also the BET surface area of the catalyst. Increasing mole % of metal loading in the catalyst decreased the apparent activation energy for methane combustion and also the BET surface area of the catalyst. In view of these, there existed an optimized mole % of metal loading where the highest catalytic activity was observed.
3

Al-Swai, Basem M., N. B. Osman, and Bawadi Abdullah. "Catalytic performance of Ni/MgO catalyst in methane dry reforming." In THE 2ND INTERNATIONAL CONFERENCE ON APPLIED SCIENCE AND TECHNOLOGY 2017 (ICAST’17). Author(s), 2017. http://dx.doi.org/10.1063/1.5005361.

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Zhu, Huayang, and Greg S. Jackson. "Transient Modeling for Assessing Catalytic Combustor Performance in Small Gas Turbine Applications." In ASME Turbo Expo 2001: Power for Land, Sea, and Air. American Society of Mechanical Engineers, 2001. http://dx.doi.org/10.1115/2001-gt-0520.

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The development of lean-premixed catalytic reactors for ultra-low emissions combustors in gas turbines presents many design and operability challenges that are not addressed with conventional steady-state reactor models with one-step chemistry mechanisms. These challenges include transient light-off from low temperatures, catalyst deactivation, and hysteresis in catalytic activity. To address these issues, a transient 1-D reactor model with a validated multi-step surface chemistry mechanism has been developed to explore such behavior in catalytic combustors. The surface chemistry sub-model has been incorporated for investigating lean catalytic combustion of CH4 on Pd-based catalysts. The current study investigated the effects of operating conditions — such as pressure, inlet temperature, and velocity — on catalytic reactor ignition and deactivation. The transient modeling provides curves for reactor light-off for a range of inlet pressures and velocities and reveals conditions wherein Pd-catalyst undergoes reduction/deactivation. Model results are compared with some experimental measurements and implications for catalytic combustor design and operation for gas turbine applications are discussed.
5

Dutta, P., D. K. Yee, and R. A. Dalla Betta. "Catalytic Combustor Development for Ultra-Low Emissions Industrial Gas Turbines." In ASME 1997 International Gas Turbine and Aeroengine Congress and Exhibition. American Society of Mechanical Engineers, 1997. http://dx.doi.org/10.1115/97-gt-497.

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The goal of the Advanced Turbine Systems (ATS) program is to develop a high thermal efficiency industrial gas turbine with ultra-low emissions (<10 ppmv NOx, CO and UHC @ 15% O2) over the 50 to 100% load range. Catalytic combustion was chosen as an approach likely to meet ATS emissions goals. A subscale catalytic combustor development program was designed to develop a technical knowledge base for catalyst design (catalyst construction, length), performance (ignition, activity and emissions) and operating limitations (fuel-air turndown and sensitivity to combustor operating variables). A novel catalyst design with preferential catalyst coating to limit substrate temperatures was used in the tests. The catalytic combustor consists of a fuel-air premixer, catalytic reactor and a post-catalyst zone for completion of homogeneous gas phase reactions. In situ measurements of mean fuel concentrations at the exit of the premixer were completed to characterize fuel-air premixing levels. Performance of the catalyst was monitored through global emissions measurements at the exit of the post-catalyst combustor under simulated engine conditions, and measurement of catalyst substrate temperatures. Ultra-low emissions were achieved for relatively uniform fuel-air premixing (<10% peak to peak variation in fuel concentration) with higher inhomogeneities (>10% peak to peak variation) leading to either locally high or low substrate temperatures. Regions with low substrate temperatures led to high CO and UHC emissions. Modeling of post-catalyst homogeneous reactions using a standard stationary, one-dimensional, laminar premixed flame formulation showed good agreement with measurements. In short term tests, the catalysts showed the desired chemical activity and ability for multiple light-off. The subscale combustor development work provided the necessary technical information for full scale catalytic combustion system development for the ATS gas turbine.
6

Manrique Carrera, Arturo, Jeevan Jayasuriya, and Torsten Fransson. "Staged Lean Catalytic Combustion of Gasified Biomass for Gas Turbine Applications: An Experimental Approach to Investigate Performance of Catalysts." In ASME Turbo Expo 2013: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/gt2013-95339.

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Emission demands for gas turbine utilization will become more stringent in the coming years. Currently different techniques are used to reach low levels of NOx emissions. One possible solution is the Staged Lean Catalytic Combustion. In this concept a catalysts arrangement is used to generate high temperature combustion gases. The high temperature gases could be used to feed a second combustion stage in which more fuel is injected. In this work a series of experiments were performed at the Catalytic Combustion High Pressure Test Facility at the Royal Institute of Technology (KTH) in Sweden. The fuel used was a simulated gasified biomass and the catalytic combustor consisted of an arrangement of different catalysts, e.g. bimetallic, hexaaluminates, and perovskites catalysts. These were used as, ignition catalyst, medium temperature catalyst and high temperature catalyst respectively. The tests were performed between 5 and 13.5 bar, and the overall conversion varied between 60% and 70% and the temperature of flue gases could reach 750°C and contains high level of oxygen. The determining factor to control the exit gas temperature was the richness of the mixture (λ value). On the other hand, the increased pressure had a moderate negative effect in the overall fuel conversion. This effect is stronger at leaner mixtures compared to richer ones. Moreover, λ value and also pressure affected the temperature distribution along the reactor. The utilization of a lean catalytic combustion approach makes possible the use of a post catalytic combustion. In this region additional fuel is injected to fully burn the exiting gases and increase the exit temperature to the desired levels. This staged lean catalytic combustion approach could resemble moderate levels exhaust gas recirculation techniques and/or high air temperature combustion and it is also briefly examined in the present work.
7

Ghazvini, Mohammad, and Vinod Narayanan. "Performance Characterization of a Microscale Integrated Combustor Recuperator Oil Heat Exchanger." In ASME/JSME 2011 8th Thermal Engineering Joint Conference. ASMEDC, 2011. http://dx.doi.org/10.1115/ajtec2011-44633.

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A two-dimensional numerical model of an integrated microscale hydrogen-air combustor, recuperator, and oil heat exchanger is presented. The recuperator is used to preheat the incoming reactant gases entering the combustor. Heterogeneous catalytic combustion occurs on the walls of the microchannel in the presence of platinum catalyst. The maximum oil temperature was constrained based on the properties of the fluid used. The recuperator gas outlet temperature was constrained to be larger than the saturation temperature for water to avoid condensation in the exhaust gas stream. The performance of the combustor is documented for variations in geometric and fluidic parameters. The geometric parameters include the length and location of the catalyst bed, and the length of the device. Varied fluidic parameters include the oil inlet temperature, flow rates of oil and reactants, and the equivalence ratio of the reactants. For the range of parameters studied, results indicate that increasing the catalytic surface length as well as the channel length increases the efficiency.
8

Wilson, John Parley, and Dan DelVescovo. "Algorithm to Calibrate Catalytic Converter Simulation Light-Off Curve." In WCX SAE World Congress Experience. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 2024. http://dx.doi.org/10.4271/2024-01-2630.

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<div class="section abstract"><div class="htmlview paragraph">Spark ignition engines utilize catalytic converters to reform harmful exhaust gas emissions such as carbon monoxide, unburned hydrocarbons, and oxides of nitrogen into less harmful products. Aftertreatment devices require the use of expensive catalytic metals such as platinum, palladium, and rhodium. Meanwhile, tightening automotive emissions regulations globally necessitate the development of high-performance exhaust gas catalysts. So, automotive manufactures must balance maximizing catalyst performance while minimizing production costs. There are thousands of different recipes for catalytic converters, with each having a different effect on the various catalytic chemical reactions which impact the resultant tailpipe gas composition. In the development of catalytic converters, simulation models are often used to reduce the need for physical parts and testing, thus saving significant time and money. However, calibration of these models can be challenging and requires significant time and effort. Catalytic converter models require the specification of input conditions (i.e. temperature, flowrate, and species concentrations). Then they calculate the predicted exhaust gas composition by simulating the chemical reactions occurring within the catalyst. These simulations can then be calibrated and validated against experimental measurements. The chemical reaction rates in the model utilize an Arrhenius expression which includes two tunable variables, the pre-exponential factor (A), which is a measure of collision frequency, and the activation energy (E), which is a threshold to overcome for molecules to react. Calibration of these values often requires many iterations, checking the results and adjusting to eventually identify the best values. In this work, an optimization algorithm was developed to automatically tune these parameters to best simulate catalyst light-off data. This algorithm is presented. It has the potential to significantly reduce time in calibrating catalyst models.</div></div>
9

Cowell, Luke H., and Matthew P. Larkin. "Development of a Catalytic Combustor for Industrial Gas Turbines." In ASME 1994 International Gas Turbine and Aeroengine Congress and Exposition. American Society of Mechanical Engineers, 1994. http://dx.doi.org/10.1115/94-gt-254.

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A catalytic combustion system for advanced industrial gas turbines is under long tern development employing recent advances in catalyst and materials technologies. Catalytic combustion is a proven means of burning fuel with single digit NOx emissions levels. However, this technology has yet to be considered for production in an industrial gas turbine for a number of reasons including: limited catalyst durability, demonstration of a system that can operate over all loads and ambient conditions, and market and cost factors. The catalytic combustion system will require extensive modifications to production gas turbines including fuel staging and variable geometry. The combustion system is composed of five elements: a preheat combustor, premixer, catalyst bed, part load injector and post-catalyst combustor. The preheat combustor operates in a lean premixed mode and is used to elevate catalyst inlet air and fuel to operating temperature. The premixer combines fuel and air into a uniform mixture before entering the catalyst. The catalyst bed initiates the fuel-air reactions, elevating the mixture temperature and partially oxidizing the fuel. The part load injector is a lean premixed combustor system that provides fuel and air to the post-catalyst combustor. The post-catalyst combustor is the volume downstream of the catalyst bed where the combustion reactions are completed. At part load conditions a conventional flame bums in this zone. Combustion testing is on-going in a subscale rig to optimize the system and define operating limits. Short duration rig testing has been completed to 9 atmospheres pressure with stable catalytic combustion and NOx emissions down to the 5 ppmv level. Testing was intended to prove-out design elements at representative full load engine conditions. Subscale combustion testing is planned to document performance at part-load conditions. Preliminary full-scale engine design studies are underway.
10

Walke, P. V., N. V. Deshpande, and A. K. Mahalle. "Performance and Emission Characteristics of a Diesel Engine Using Catalysts With Exhaust Gas Ricirculation." In ASME 2006 International Mechanical Engineering Congress and Exposition. ASMEDC, 2006. http://dx.doi.org/10.1115/imece2006-14484.

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Testing of catalytic converter with exhaust gas recirculation system for diesel engine to reduce pollute gases is chosen for present work. The emphasis is given on hydrocarbon (HC), carbon monoxide (CO) and oxides of nitrogen. The catalytic converter was developed with variations of catalyst plates. Perforated plates of copper and combination of copper oxide and cerium oxide (CeO2 +CuO) were used as the catalyst. Copper spacer was used in between plates to vary the distance. Secondary air was injected into the converter to aid oxidization of HC and CO. Experimental study was carried out on computerized kirloskar single cylinder four stroke (10 B.H.P, 7.4 KW) diesel engine test rig with an eddy current dynamometer. The converter was tested with various combination with exhaust gas re-circulation (EGR) system. There are some improvements in the reduction and conversion efficiency of HC & CO. Exhaust gas re-circulation has proved to be effective in reducing NOx.

Reports on the topic "Catalyc performance":

1

Defoort, Willson, and Olsen. L51849 Performance Evaluation of Exhaust Catalysts During the Initial Aging on Large Industrial Engines. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), June 2001. http://dx.doi.org/10.55274/r0011213.

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An investigation of catalyst performance during the initial aging process, providing insight into the deactivation rate of the catalyst and assisting in predicting the operational lifetime of the catalyst was preformed. The information gained through the test program provides a mechanism to assist in developing new technologies geared at reducing engine emission while providing improvements in efficiency, reliability, and operability for the aging industrial reciprocating engine fleet. Two natural gas lean burn engines, a 2-stroke, large bore slow speed and a 4-stroke medium bore medium speed, were operated at pre-determined conditions in conjunction with an oxidation catalyst. The aging process of the catalysts was observed. The research concluded that the catalyst performance is much lower than anticipated,particularly in relation to the aging process. During the aging process for the large bore 2-stroke engine (about 200 hours) the catalyst efficiency drops from 95% to 80% for CO and from 75% to 45% for CH2O. Results for the medium bore 4-stroke engine are better as a result of nearly 200°F higher catalyst temperatures. During aging (approximately 150 hours) the catalyst efficiencies are reduced from 99.2 to 97.7% for CO and from undetectable post catalyst levels (essentially 100% removal) to 67% for CH2O.
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Chapman and Toema. PR-266-09211-R01 Physics-Based Characterization of Lambda Sensor from Natural Gas Fueled Engines. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), November 2012. http://dx.doi.org/10.55274/r0010022.

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The increasingly strict air emission regulations may require implementing Non-Selective Catalytic Reduction (NSCR) systems as a promising emission control technology for stationary rich burn spark ignition engines. Many recent experimental investigations that used NSCR systems for stationary natural gas fueled engines showed that NSCR systems were unable to consistently control the exhaust emissions level below the compliance limits. Modeling of NSCR components to better understand, and then exploit, the underlying physical processes that occur in the lambda sensor and the catalyst media is now considered an essential step toward improving NSCR system performance. This report focuses on modeling the lambda sensor that provides feedback to the air-to-fuel ratio controller. Correct interpretation of the sensor output signal is necessary to achieve consistently low emissions level. The goal of this modeling study is to improve the understanding of the physical processes that occur within the sensor, investigate the cross-sensitivity of various exhaust gas species on the sensor performance, and finally this model serves as a tool to improve NSCR control strategies. This model simulates the output from a planar switch type lambda sensor. The model consists of three modules. The first module models the multi-component mass transport through the sensor protective layer. The second module includes all the surface catalytic reactions that take place on the sensor platinum electrodes. The third module is responsible for simulating the reactions that occur on the electrolyte material and determine the sensor output voltage.
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Olsen, Daniel, Bryan Hackleman, and Rodrigo Bauza Tellechaea. PR-179-16207-R01 Oxidation Catalyst Degradation on a 2-Stroke Lean-Burn NG Engine - Washing. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), May 2019. http://dx.doi.org/10.55274/r0011586.

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Oxidation catalysts are often utilized to reduce carbon monoxide, formaldehyde, and volatile organic compounds in order to meet emissions regulations for large bore natural gas engines. These catalysts degrade over time and need to be replaced or regenerated to maintain emissions compliance. This work evaluates the effectiveness of catalyst regeneration, or catalyst washing. The evaluation is performed by utilizing field and laboratory slip streams combined with catalyst module performance (reduction efficiency) measurements and catalyst material surface analysis to quantify catalyst poisons.
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Glen R. Longhurst and Robert J. Pawelko. Modified MTS MRB500 CATALYST PERFORMANCE TEST. Office of Scientific and Technical Information (OSTI), October 2008. http://dx.doi.org/10.2172/944210.

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Bauza, Rodrigo, and Daniel Olsen. PR-179-20200-R01 Improved Catalyst Regeneration Process to Increase Poison Removal. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), June 2021. http://dx.doi.org/10.55274/r0012106.

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In this work, the details of catalyst poison deposition are studied, and new catalyst restoration methods are explored. Lubrication oil makes its way through the combustion chamber and into the exhaust system, depositing poisons onto the catalyst and degrading catalyst performance. To estimate the degradation rate of the units and to find the best restoration method, two identical alumina-platinum oxidation catalysts were used in a dual setting, combining a field degradation engine and a laboratory testing engine. In order to find the best restoration process, the combination of both baking and washing is tested with poison deposition and performance analysis, and a hydrogen reduction is tested for the restoration of the platinum crystallites. The units were aged, then restored with the industry-standard washing procedure, then aged again until reaching non-compliance with emissions standards, and then restored a second time with a modified version of the industry-standard washing process that combines baking and washing. There is a related webinar.
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Johnson, Terry Alan, and Michael P. Kanouff. Performance characterization of a hydrogen catalytic heater. Office of Scientific and Technical Information (OSTI), April 2010. http://dx.doi.org/10.2172/992333.

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Badrinarayanan and Olsen. PR-179-11201-R01 Performance Evaluation of Multiple Oxidation Catalysts on a Lean Burn Natural Gas Engine. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), August 2012. http://dx.doi.org/10.55274/r0010772.

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Two-way catalysts or oxidation catalysts are the common after-treatment systems used on lean burn natural gas engines to reduce CO, VOCs and formaldehyde emissions. The study evaluates the performance of oxidation catalysts from commercial vendors for varying catalyst temperature and space velocity. For this study, a part of the exhaust from a Waukesha VGF-18 GL lean burn natural gas engine was flowed through a catalyst slipstream system to assess the performance of the oxidation catalysts. The slipstream is used to reduce the size of the catalysts and to allow precise control of temperature and space velocity. Analyzers used include Rosemount 5-gas emissions bench, Nicolet Fourier Transform Infra-Red spectrometer and HP 5890 Series II Gas Chromatograph. The oxidation catalysts were degreened at 1200oF (650oC) for 24 hours prior to performance testing. The reduction efficencies for the emission species varied among the oxidation catalysts tested from different vendors. Most oxidation catalysts showed over 90% maximum reduction efficiencies on CO, VOCs and formaldehyde. VOC reduction efficiency was limited by poor propane emission reduction efficiency at the catalyst temperatures tested. Saturated hydrocarbons such as propane showed low reduction efficiencies on all oxidation catalysts due to high activation energy. Variation in space velocity showed very little effect on the conversion efficiencies. Most species showed over 90% conversion efficiency during the space velocity sweep. Adding more catalyst volume may not increase the reduction efficiency of emission species. Varying cell density showed very little effect on performance of the oxidation catalysts. The friction factor correlation showed the friction factor for flow through a single channel is inversely proportional to cell density.
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Olsen and Neuner. PR-179-12207-R01 Performance Measurements of Oxidation Catalyst on an Exhaust Slipstream. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), August 2013. http://dx.doi.org/10.55274/r0010800.

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Oxidation catalysts are effective at reducing CO, formaldehyde, and VOCs as long as the catalyst temperature is above the light-off temperature for each species. It is important to understand the effects of temperature and space velocity on regulated species in order to effectively apply oxidation catalyst technology to lean burn engines, in particular 2-stroke engines that typically have lower exhaust temperatures. Various catalysts were tested on an exhaust slipstream coupled to a 4-stroke lean-burn engine which allows tests to be conducted at different temperatures and flow rates. The effect of the oxidation catalysts on NO2 and odor are also discussed.
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Hohn and Zeng. PR-266-14200-R01 Modeling of NSCR Performance with Natural Gas Exhaust. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), August 2016. http://dx.doi.org/10.55274/r0010880.

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There is a need for highly efficient processes for treating the engine exhaust from natural gas-powered engine in order to meet current and potential environmental regulations. One means to do so is to employ dithering, where the air to fuel ratio sent to the engine is cycled between high and low values around the stoichiometric point. There is limited experimental data to suggest that dithering can be effective, but little is known about how dithering impacts the performance of a three-way catalyst to destroy pollutants from natural gas-powered engines. This research simulates the performance of a three-way catalyst for destruction of pollutants when dithering is applied to a natural gas engine. The model is used to understand the detailed chemistry occurring during dithering.
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Fairbridge, C., and J. F. Kriz. Catalyst performance in hydrotreating coal-derived middle distillate. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 1985. http://dx.doi.org/10.4095/302557.

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